Steam turbine operation handbook

Electric Motor Rating 9 K. Speed — rpm. Speed Motor : air mixture from the chimney steam condenser. Rating — 8. Head — metres of water Seven Numbers of oil pumps for column. Pressure — 50 atg. Rating Head — metres of water — 30K.

Quantity Rating — 0. Np — KW. Pressure at delivery — Area on steam side — 30 sq. Squirrel cage induction motor : Quantity of steam for condens Capacity — K.

Designed pressure on steam side Each of area — 80 Sq. Designed pressure on water side Number of ' U ' tubes — Test pressure on steam side with Resistance on water side at a flow water — 3 atg. Test pressure on water side Test pressure on waterside — — 42 atg. Each of area on steam side Quantity of steam for condensing — 80 sq.

Resistance on water side at a Resistance on water side at a flow flow of Test pressure on water side Safety valve on steam side is set — 42 atg. Test pressure on water side One chimney steam condenser — Test pressure on steam side with Vertical Design : water — 9 atg.

Resistance on water side at a flow Low pressure heaters IIIrd of Each : Setting pressure for safety valve Area on steam side — sq. Number of 'U' tubes — on steam side — 20 atg. Safety valve setting pressure on steam side — 6 atg. The test pressure on water side The test pressure on steam side One high pressure heater of with water — 9 atg. VHIth stage heating — Vertical Design : Test pressure with water — 9 atg. Vllth stage heating — Vertical Test pressure on water side — atg. Design : Test pressure on steam side with Area on steam side — sq.

From this cooling water in the condenser. Through the impure condensate tank, which is inlet steam branches each conden- at the condenser pressure. The ser, on the water side is vertically samples of the impure conden- divided, into two independent sate can be drawn by the sample double path circuits which enables collecting vessel, which has valves the cleaning of water space of the for connecting to the vacuum and condensers in stages, during the to the atmosphere.

On the com- operation of the turboset at mon piping, for draining off the reduced outputs as per diagram impure condensate to the impure condensate tank, a measurement RC In of both the condensers which are case the impure condensate tank on the common cooling water has not been envisaged and not circuit, should be put out of been provided, this additional operation.

Also the sample collect- which are put out of operation ing drains are blinded. The On the steam side, both the con- water chambers are separated densers are inter-connected by from the steam space by means a balancing piping connecting the of the tube end plates, which are super structures of the conden- painted with two coats of APCO- sers by which the pressure in DUR 66 Black on the water side, both the condensers are equalised.

These facilities how- The inner surface of the steam ever will not be available, if the space is painted with one coat impure condensate tank is not of wash-primer, and one coat of provided. The ductivity is noted at the suction spoiled paint work must be of the condensate pumps, by repaired with the same coats of opening these branches individu- paint as stated above. When the valve for which have slightly higher draining the condensate to the size holes for cooling tubes. The loss of con- space of the condenser, is divided densate has to be then continu- by longitudinal partitions into 10 ously made up by admitting the sections.

The branches for the chemically treated water. In the sensing elements of the permanent case of the inner six sections, condensate conductivity measure- there is no possibility for draining ment system are built-in and off the condensate, and it is blinded in each section.

The assumed that in case of heavy condensate from individual sec- leakage, leading to an impure tions spills over from each section condensate in the 6 sections, the into a common longitudinal col- turboset will be stopped to remove lector hot well and is deaerated.

From the hot well, the condensate The instrument for continuous is then led to the suction of the measurement of the conducti- condensate pumps. For the quick each of the two hot wells to the destroyal of vacuum during the condensate pumps. The increase s to p p in g o f th e tu r b o s e t s o of conductivity to 3 micro mhos as to avoid the unnecessary cm. The conducti- cooling of the turboset by the vity and the levels in the hot well chilled gland steam resulting by and in the feed water tank must expansion due to the vacuum be followed carefully and if neces- condition, a branch with an sary, the make up water is added electrical valve is provided on by the automatic regulation in the air piping from the condenser the incoming demineralised water to the ejectors, with which it is line.

The regulating valve is possible to suck the air into the controlled by the impulse from condenser from the atmosphere. The steam air with a water seal so that its mixture is sucked off from both perfect tightness is ensured during the sides of the condenser across normal operation of the turboset. After the erection of condenser The tightness of the entire vacuum at the site, and during the repairs system of the turboset can be of the condenser, the pressure tested during operation by tempo- test on the water side is performed rarily closing the valve on the at a pressure of 3.

The air line before the ejectors. In the average fall of the vacuum start- case of the latter test, the conden- ing from the second minute ser must be solidly supported by after the closing of air valve the packing plates, so that the is less than 3 mm of Hg per increase in weight is not taken up minute. The condenser and the by the springs and undue strain whole vacuum system of the does not fall on the LP casing turboset is safeguarded against the inner over pressure by the All the fittings in the vacuum explosion membrances, located side are provided with gland on the top half of the exhaust hood sealing of the spindles by conden- of the LP casing of the turbine.

It consists of the steam duplex type, provided with two chambers from which the steam first stage ejectors and two second is led through the nozzle into the stage ejectors, which are placed mixing chamber, to which is on the common body shell. The connected the mixing nozzle with body consists of a shell welded the diffuser. The working steam from plates, which is divided led into the ejector through the with partition walls into two steam chamber flows through independent parts, and each part the steam nozzle attaining a is further divided into the top high velocity.

This creates a. The tube and the air sucked from the plates into which the tubes are condenser to the mixing chamber roller expanded are welded at entrapping it in the flow of steam, the ends of the shell. The ejector rests on the with a pressure gauge for the foundation by meas of the foot measurement of steam pressure plates welded on to the bottom in the steam chamber ; and a part of the shell. This ejector sucks off the steam air mixture from the condenser Thermowells are provided for the during operation because of the measurement of temperature of : leakage in the flange connections 1 Steam space of Inter-con by defective sealing of glands.

The ejector works with the super- 2 Condensate inlet and outlet. The steam chamber to deaerate the water jet air ejector is provided with chamber now and then during the necessary measuring instru- operation. For the full output, one half of the ejector, is enough and the The steam air mixture The detailed description and the from the main condenser is sucked instructions for the operation into the first stage and along with of the various pumps and their the working steam of 1 stage driving motors pertaining to the is exhausted into the inter- auxiliaries of the turboset is condenser where the major por- supplied seperately.

Before ope- tion of steam condenses. The rating any one of the pumps, condensate of this steam is led it is necessary to ensure sufficient to the condenser through a siphon flooding of the suction of the from the bottom part of the pump, by ensuring the proper inter condenser. The non-con- level in the suction sump or in densed steam and air from the the collector, so that the impel- inter condenser is then sucked lers are safely submerged and do off by second stage and, along not suck in air or steam.

The with its working steam is exhaus- space of water chamber of the ted into the after-condenser. The condensate is incidental clogging up of the drained by the float type steam suction of the pump.

The lubri- trap into the main condenser. The con- reduction station. In case C. Scheme and before opera- of improper insulation resistance, ting the pump, the respective it is necessary to dry the motor as valves on the incoming water per the instructions of the manu- lines must be kept open. The facturer. Oil or grease in, regulated in such a way that the current loading of the motors does the individual bearings must be not exceed the values given on regularly topped up or changed, the temperature of the bearings the name plate.

It is necessary is to be checked, and the maxi- to adhere to the instructions mum permissible values are given of the manufacturer of the motors, in the respective instructions. The procedure of manipulation of the valves gives rise to an increase of tem- perature as in the case of in- in the respective circuits of the sufficient lubrication.

The cooling water is supplied to the entire system from a cooling water supply duel. A major portion of the cooling water is supplied to the condenser. Four valves are mounted on the outlet of the condenser for putting out of operation the individual halves of the condenser for tube cleaning, during operation. Part of the cooling water is supplied to the oil coolers, coolers for the sealing oil and to the condensate coolers if condensate is used for cooling of Hydrogen coolers.

For the cooling of the auxiliary equipments, cooling water from a separate cooling water circuit is used. The water is supplied by booster pumps. The changes in the THE CONDENSER level are mechanically transferred S : at the given proportion as the changes in the position of the The level controller maintains an cons 11 which is positioned approximately constant conden- against the end of the piston 17 sate level in the hot well during of the regulating slide 4.

The the running of the turboset, and pressure water taken from the thus maintains a practically cons- incoming piping through a filter, tant suction head for the conden- is led through the pipe union 52 sate pumps. Its construction and into the amplifier provided at location ensures the flow of the bottom portion of the slide minimum required quantity of 4. On the top surface of the condensate for the cooling of amplifier, the full pressure of steam jet air ejectors. Because of a change of controller 6 is connected at its position of the cone 11 , there bottom part with the hot well is a change in the pressure of and at its top with the steam water below the piston and due space of the condenser, so that to that, there is a change in the the level in the float chamber position of the slide 4.

Each corresponds to the level in the particular position of the float condenser hot well. Minimum level The float with the lever 8 corresponds to the highest posi- follows the level of the conden- tion of the slide and vice versa. The gear segments 3 and 5 are used as a The main flow part consists of a transfer mechanism between the casing with three ways along with level of condensate and the a regulating bush 2. The regu- position of the regulating slide lating slide 4 which has at its 4.

The flow sections are profiled in such a way as to have a linear relationship between the level and the flow quantity. At the minimum level, the ports for recirculation are fully open, and the ports for the regeneration are fully closed. With the increase of level at higher loads of the turboset, the ports for recirculation, start clos- ing and the ports for regeneration start to open admitting the con- densate to the heaters.

On further rise of level, the recircu- lation will be completely closed and the entire condensate is sent towards the heaters. All the piping connected to the controller is provided with valves, so that the controller can be isolated and inspected even during the operation of turboset, and the level can be regulated by the by- pass valves in the respective piping either to the heaters or to the condenser.

The height of the level in the hot well is indica- ted by the differential pressure transmitter which gives the im- pulse. All the are heated in 8 stages by the non- valves are set for opening at a regulated extractions from the pressure of 28 atg. The 8th extraction condenser and part of condensate steam is taken from the cold through chimney steam con- reheat line.

The circuit of feed denser. The first and second stage water is protected against any of regenerative heating is done by abnormal rise of pressure by a two, double low pressure heaters relief safety valve located in the which are mounted directly in the piping before I HPH, and is set low pressure casing of the turbine to open at a pressure of atg.

In between the The condensate from the hot II and III stages of heating the well of the condenser is pumped chimney steam condenser and by condensate pumps through gland steam condenser are located the ejector, all the LP heaters, and have a common by-pass on gland steam and chimney steam the condensate side. At the full output, two 3rd, 4th and 5th low pressure condensate pumps are enough, heaters form the individual stages and the third serves as a of heating.

At lower loads, pass. The deaerator along with one pump is enough for pumping the feed water tank forms the the condensate. The second one next stage of heating, heated by is kept ready for starting, at the the steam from the VI extrac- increase of the pumped quantity tion. Signalisation is pro- protected from any abnormal vided, for a quick checking of rise of pressure by relief safety pump in operation. CONDENSER The stages of heating in gland On exceeding the first level of steam and chimney steam con- condensate in any one of the densers are given in the section heaters, level signalisers give about gland steam system On attaining the faulty maximum level, the second level signaliser give the impulse for tripping the turboset and also for optical and acoustic signalisation.

The stopping of the turboset by the impulse from second level signaliser can be avoided by opening the by-pass on the main condensate and by closing the inlet and outlet of the main condensate to that half of the heaters where the signalisation of level rise has occured.

In sate booster pumps. The heating case of a breakdown of any steam condensate from the V and one of the heaters, both must IV extractions are cascaded in be put out of operation. The con- two independent level signalisers. In the extract! It is therefore neces valves are signalled. Sucking off sary to manually open the by-pass of the air and the non-condensing of the heater on the water side, gases from the steam space of III and afterwards to close the valves LPH takes place continuously on the inlet to III LPH and through an orifice and a valve to on the outlet of IV LPH, and the condenser.

The valve during then to close the valve on the normal operation is kept open. For full output, one The expander, during normal condensate booster pump is operation, is at a pressure equal enough and the second serves as to that of III LPH. During pressure transmitter through an normal operation, the condensate electronic regulator on the servo- of heating steam always cascades motor at the level controller.

The from the higher stage to the lower level controller is mounted on stage. Con- sate from V LPH is led directly densate of the heating steam to the expander. Similarly, con- is led to the circuit of main densate of heating steam from condensate before, III LPH or HPH can be led directly to the at the low level, and recirculated expander, in case V LPH is out back to the expander by which of operation.

The piping of release circuit of main condensate or steam from the expander is also back to the expander. The condensate into the main conden- 96 sate circuit. At the minimum level, the ports 1 To stop the working booster for allowing condensate to the pump along with the simul main condensate cycle are fully taneous interlocking for the closed and all the condensate standby pump ; of the heating steam is recircu- lated back to the expander. At the minimum level in the expander, the level signalisers 4 Optical and acoustic signali- mounted on it give the impulse sation.

At the level increase ing of the working booster pump above the minimum level, im- does not occur. For a new, pulse is given by the second level automatic starting of the booster signaliser for the starting of the pump the valve on the draining booster pump. The running and of condensate from the expander the switching off of any of the to the condenser must be closed booster pumps is signalled. By the rential pressure transmitter manual closing or opening the through an electronic regulator at automatics are switched off, and the servomotor.

The maximum the closing or opening of the opening of the level regulator is valves is done by operating the signalled by a limit switch on servomotor from the floor or the servomotor.

At a non-per- from the block control room. For safeguarding the turbine against the back flow of steam, That is— a non-return quick closing extrac- 1 to close the valve on the tion valve is provided on the incoming steam line to III fourth extraction near the turbine, LPH and IV LPH : and an electrically driven valve 2 to close the non-return, before the heater. The conden- ling of the performed action.

The Further manipulation for stop- draining of condensate is regula- ping III and IV LPH, and the ted by the electrical regulating expander on the steam side, and valve which gets the impulse ensuring the draining of heating from the differential pressure steam condensate from the V transmitter through an electric LPH is given in detail in the regulator.

In case of a fault previous article. The maxi- mum opening of the regulating valve is optically signalled by a limit switch at the servomotor of the valve. During the normal nal heating is closed, it connects operation, the condensate is hea- back the gland steam to V ted by steam from V extraction extraction.

The change in the of the turbine, as in case position of the valve is signalled of lower loads, and during at the fall out of generator. The impulses for opening on the V extraction. For the steam turbine driving an electric 1 Steam Properties 1 an experimental turbine- problem that it is impossible to overcome is that. Steam Engineering Basics. Berkeley and 2 The.

DlNG I. The low operating cost of steam power plants is a result of plant that are required for safe efficient reliable combined-cycle systems. Operation below design inlet steam To protect Peter Brotherhood steam turbines during abnormal operation, Operation of the manual hand trip and During the design stages of a steam turbine, EXe Excitation Control for Steam Turbine Generators Large steam turbine generators have potential three protocols support full operation and monitoring of Swagelok Energy Advisors, Inc.

Technology Characterization — Steam Turbines. See as annex of turbine inlet steam state which shows the relationship between inlet temperature and pressure of main steam valve in cold state start. If you want to make the temperature of steam chamber meet the required value, this parameter relationship should be obeyed.

Check and make sure that main oil pump outlet pressure is 2. Stop AC lubricate oil pump, sealing oil standby oil pump and put them in standby. No reproduction or networking permitted without license from Shel 20 0 KB Read more. Properties of Steam 65 2 6MB Read more. Properties of Steam 28 0 KB Read more. Your name. Close Submit. Our partners will collect data and use cookies for ad targeting and measurement.

Unit load and pressure complies with regulated range. The test starts. After TV1 fully closed, open it by speed of 1.

It should be confirmed from CRT and local that valves are open. When GV opened again and reach to the position same as the position before test, test is over. During close or start, press Intermit Test button if any abnormity occurs and valves recover to status before test. Test other main steam valves according to above process. Pay attention to unit load and axial displacement variation.

Test personnel should be in contact with main control room and open test oil discharging valve slowly. According to periodic test regulations, test should be done once per month, rest records should be taken and analyzed and compared with former test record. Reason should be found out and it should be cleaned if any error is found. This test must be done before starting the turbine and after protection devices are calibrated and set in unit major maintenance and minor maintenance.

The production chief and engineers of the test must be at site and strictly execute operation and supervision mechanism, and special person will be responsible for operation and supervision.

It should be confirmed that unit runs normally and all test meters indications are right before test. Choose online test on CRT of emergency trip system. Check and make sure that EH low pressure 1, 3 and trip channel 1 are bright.

Press Trip recover button, trip channel 1 light gets off. Test EH oil low pressure at B side with the same method. Test the Low lubricate oil pressure and Low vacuum with above method; press corresponding test button only during test. Put test handle at test position and keep the position. Open test valve slowly; when oil pressure reaches to a certain value, trip hammer extends and impact trip contactor and emergency trip oil drains.

Read the oil pressure through meter pressure. Close test valve and confirm that test oil pressure changes to be zero. Recover handle manually and put test handle at normal position.

Vacuum tightness evaluation standard is as following: Excellent: 0. Check air side AC sealing oil pump operating normal, oil hydrogen differential pressure is normal, air side DC sealing oil pump switch put into interlock.

Stop operating air side DC sealing oil pump. Check oil hydrogen differential pressure is 0. Close drain oil valve after confirming its normal, open differential pressure switch isolation valve, stop air side DC sealing oil pump until differential pressure recover normal. Check air side AC sealing oil pump operating normally, oil hydrogen differential pressure is 0. Slowly close air side oil pump outlet valve, when oil hydrogen reduce to 0. Continue to close air side oil pump outlet valve, oil hydrogen differential pressure should keep at the level of 0.

Confirm standby differential pressure valve can maintain oil hydrogen differential pressure is 0. When EH oil pressure drops to Over speed test must be done after unit major maintenance or half-year or one year continuous running and individual maintenance of emergency protector.

This test must be agreed by shift manager and should be charged by chief engineer. Test must be done under supervision of assigned person, and turbine engineer must direct at site. Unit running speed, vibration, axial displacement and LP steam exhausting temperature should be strictly supervised during test.

Sufficient test personnel, instrumental meters and tools should be prepared before test. After RPM stable speed, open over speed test screen. Click OK. Turbine running speed rising to mechanical centrifugal stop bolt, security system operate, turbine trip, test stop.

This test must be done before BFPT cold starting or regulating system maintenance, test have to be done before boiler burning. One main oil pump operating normally, fire-resistant fluid system operating normal. Check that quick closing valve open, open speed regulation valve and pipe regulating valve, confirm each valves switch flexible on local.

On MEH screen, push tripper button, check BFPT quick closing valve, speed regulating valve and pipe regulating should close quickly, tripper light. Test finish, recover former operating mode.

When test, should confirm whether LP main steam valve have fasten phenomenon on local. During test, should supervise BFPTs speed, vibration, axial displacement and so on parameters. Confirm running speed automatically light, boiler remote control light. Confirm quick closing oil pressure is normal, quick closing valve completely open.

When the LP main stop valve closed to required travel, the test button light will be on. During LP main stop valve test, confirm no clip phenomenon on local. After the test, the main stop valve will open automatically. The indication light of button will be off.

BFPT manual trip test should be done before the test. Check and make sure that main steam valve and governor valve close rapidly; otherwise over speed test is prohibited. Increase running speed of feed water pump turbine to normal working running speed according to normal speed rise process. Press over speed test, press electrical, make it bright. Press increase speed. HP main steam valve, LP main steam valve and LP governor valve close automatically; running speed should decrease.

After test, electrical test button extinguished. Increases the running speed of feed water pump turbine to normal running speed according to normal speed rise process. Press over speed test, press mechanical, make it bright. During mechanical over speed test, electrical trip does not work, and relative indicate lamp bright in operator station.

Press increase speed, keep rising running speed to the value of emergency protector tuning value. After mechanical test, mechanical over speed lamp extinguished.

When Latch becomes grey, signal of Oil pressure for latch not formed and Primary oil pressure low appear, oil spraying test Successful light on CRT shines.

When Latch signal appears, Oil pressure for latch not formed and Primary oil pressure low disappears at the same time. Test is completed. Shift managers instructions except for that direct endanger personal or equipment safety should be executed immediately, otherwise reason should be declared. If the shift manager insists on his instruction, it should be reported to superior manager. When accident occurs, operators should find out the main reason of accident rapidly, eliminate the threats to personal and equipment safety and try their best to ensure safe operation of non-fault equipments.

The influence of all operations to relevant systems should be fully considered during accident treatment to avoid accident expansion. Auxiliary power should be ensured not to be lost during emergency stop. When accident occurs, operators should treat the accident according the following processes:. Repeat the instruction after receiving it and report the execution result rapidly. If time is allowed, ask for instruction from the shift manager and treat it under the guidance of the shift manager.

When conditions of emergency stop of auxiliary equipment are satisfied but the protectors have not actuated, the auxiliary equipment should be stopped immediately. If the unit trips suddenly, after accident treatment and reason found out, unit should be recovered to run as soon as possible.

During fault and accident treatment, operators should not make bold to leave away from his position. If the accident treatment happens during shifts changing time, shift changing should be delayed. Before issuing handing over procedures, the operators should be continue to work until to accident treatment completion or part completion.

The successive operators should assist initiatively to treat the accident. During accident treatment, unrelated personnel are prohibited to gather in main control room or stay in fault location. After accident treatment, the duty operators should be immediately report the accident and treatment information according to the facts and, record in details about the accident time, phenomenon, development, treatment course and analysis.

All the personnel in the shift should be organized on meeting after shift to analyze the accident and prepare accident report.

Any of the following conditions occurs, stop the unit in emergency by vacuum:. Generator is in smoke or on fire or hydrogen explodes. Turbine gland sealing abrades abnormally with spark. Any of the following conditions occurs, it should be reported to the shift manager immediately and approved to stop the unit without breaking the vacuum:. All auxiliary power loses. During full load operation, temperature differences between main steam and reheat steam more than 42, or during 0 load operation, temperature differences between main steam and reheat steam more than 83 only when reheat steam temperature lower than main steam temperature.

Unit runs for more than 1min with no steam. Control steam source pressure is low or disappeared which can not maintain the original operation mode. Refer to turbine and boiler protection controller is in fault and can not be recovered. Any protector should actuate but not actuate except for stop due to vacuum break. Make sure boiler MFT operated, all coal mill, coal feeder, primary fan, sealing fan trip, all burning gun oil feeding valve and closing valve closed.

When vacuum decrease to 0, stop gland sealing steam feeding system. Check LP cylinder water sprinkler open automatically and adjust LP cylinder exhausted steam temperature is at normal range. During running speed decreasing, check carefully, notice sound in unit, check vibration, differential expansion, shaft displacement, bearing metal temperature, lube oil temperature, pressure difference between oil and hydrogen and so on of the unit.

If theres clashing inside the unit or rotor coasting time decrease obviously, prohibit to start unit again. Stop turbine and boiler by normal operation. If theres clashing inside the unit or rotor coasting time decrease obviously, prohibit to Complete other operations for stopping the unit. If load changes due to working conditions such as protector action, it should be treated according to relevant regulations.

If accumulated time exceeds h, unit should be stopped as fault stop when temperature exceeds Unit runs within temperature of with annual accumulated time of no more than 80 hours; if the time exceeds 80 hours, unit should be stopped immediately as fault stop. If steam temperature exceeds , unit should be stopped as fault stop immediately. During treatment, if main steam and reheating steam temperature continues to decrease to be 83 lower than rated value or steam temperature decrease rapidly more than 50, unit should be If there is no obvious fault, report to the shift manager immediately and prepare to increase the load.

Pay attention to minimum flow valve action of feed water pump. Supervise and regulate water levels of condenser, deaeratoor and heaters. Maintain the auxiliary steam head pipe pressure to be normal. Check whether cooling water tower level is normal or not, otherwise supplement water timely. If condensing water rigidity and conductivity rise which show stainless steel pipes leak, stop the unit or find out the leakage according to actual conditions. If vacuum continues to drop, load should be decreased.

If vacuum drops to When steam exhausting temperature rises to 70, LP cylinder spraying water valve should be opened and fully open the spraying water when the temperature rises to 80; if the temperature rises to , unit should be stopped as fault stop.

There is steam leakage or water drop spraying at steam pipe flange, valve stem, cylinder combination surface and gland sealing. Temperature difference between up and down of HP, IP cylinder more than Contact with the shift manager to restart the unit.

At the same time, supervision should be enhanced for sound inside turbine, rotor eccentricity and turning gear current. If it is confirmed that blades are broken, unit should be stopped immediately for treatment. Over limit running is prohibited. Thrust bearing and its returning oil temperature are abnormally high. Unit vibration may be high. Turbine trips when it reaches to protector actuation value. Unit is in overload or unit load, steam flow changes suddenly. Under the same load, steam parameters are on the low side, or working condition of steam extraction changes suddenly.

There is water impact in turbine. Thrust pad abrades. Blades are seriously dirty. Blades break. Condenser vacuum is low. Axial vibration is abnormal. Generator rotor is in axial moving. Frequency decreases. Re-heater safety valve actuates. If axial displacement is abnormal during operation, immediately check and make sure that whether thrust pad temperature rises or not, whether there is abnormal sound inside turbine or not, whether lubricate oil pressure and temperature are normal or not, unit vibration is normal or not, steam parameters and condenser vacuum are normal or not.

If it is due to above parameters abnormity, the parameters should be regulated to be normal. Report to the shift manager and decrease unit load properly to recover axial displacement, returning oil temperature and thrust bearing temperature. If it is caused by load or steam parameter changing, it should keep load stably, adjust steam parameter to normal value. If it is due to blade break or water impact inside turbine, unit should be stopped immediately.

If shaft displacement increasing, and accompany with abnormal sound or big vibration of unit, break vacuum and stop unit at once. When axial displacement rises to up limit value but protector does not actuate, unit should be stopped in emergency. Turbine lubricate oil system fault Lubricate oil pressure drops.

Lubricate oil temperature rises abnormally. Main oil tank level drops. Lubricate oil quality is unqualified. Oil pipes leak. Phenomenon 1 All local meters and CRT display lubricate oil pressure drops.

Reason and treatment 1 Main oil pump or oil injector works abnormally, AC lubricate oil should be started; unit should be stopped as fault stop if main oil pump works extremely abnormally. Lubricate oil pressure drops to 0. If supporting bearing temperature rises abnormally and is close to limit, unit should be stopped immediately as fault stop and break the vacuum.

Confirm the reason and treat it correspondingly. If oil pipeline is seriously broken, decrease load or stop the unit in emergency according to actual conditions. Make sure that oil is sufficient for inertia when stop the unit. Sealing oil system is in fault and leaks oil, treat it according to regulations for fault treatment in sealing oil system. Oil cooler leaks. Transfer it to standby oil cooler for operation and isolate it for treatment.

Oil purifying device is in fault and leaks oil, oil inlet valve of the device should be closed immediately and oil purifying device should be stopped.

For new unit or unit after maintenance, mechanical impurity or water is brought in due to incompletely cleaning of oil system. Oil purifying or changing should be enhanced. Gland sealing supplying steam pressure is high, which makes moisture in oil increases. Under the condition of not affecting condenser vacuum, regulate bearing steam supplying pressure to be lower and gland sealing heater negative pressure to be higher properly. There is over temperature point in oil system and oil is aging.

Oil filtering and changing should be enhanced and over temperature points should be eliminated. Turbine bearing temperature high CRT shows bearing temperature is high or alarms. Bearing returning oil temperature indication is high.

Unit vibration may be higher. Lubricate oil pressure is low or oil is unqualified. Bearing oil inlet and outlet are not smooth. Unit vibrates acutely. Bearing is damaged. Gland sealing leaks steam seriously. Unit is in overload, steam extraction system, vacuum system are running abnormally; thrust bearing temperature and returning oil temperature will rise. If oil is unqualified, oil filtering and changing should be enhanced. If oil is aging seriously, unit should be stopped according to requirements.

Thrust bearing temperature rises due to over load, unit load should be regulated. If gland sealing leaks too much steam, gland sealing steam pressure should be properly decreased under the precondition of ensuring condenser vacuum. Supporting bearing temperature reaches to or thrust bearing temperature reaches to and its returning oil temperature reaches to 77; if it is treated but with no effect, unit should be stopped as fault stop.

EH oil system fault Oil pressure swings. Oil pressure drops. Oil tank level decreases. Oil pipe leaks. Oil temperature is abnormal. Oil is unqualified. When EH oil pressure swings, running oil pump should be checked: whether overflow valve acts or not, whether oil tank level is normal or not; check working condition of standby oil pump outlet check valve.

If the oil pump does not work normally, oil pump should be transferred. Oil pressure drops, it may due to oil pump not working normally, system leaking, strainer block or overflow valve action; it should be treated according to different conditions: 1 If oil pump does not work normally, standby oil pump should be transferred for operation. When oil tank level decreases to mm, alarm sends, oil should be supplemented timely. Oil level drops generally because of oil pipes leak or oil cooler leak.

If it is the reason, the leaking point should be isolated, if it can not be isolated and oil level continues to drop, unit should be stopped for treatment. When oil temperature is abnormal, heating pump should be checked, cooling water Sealing oil pressure low Sealing oil pump does not run normally.

Sealing oil strainer is seriously blocked. Sealing pad leaks oil seriously. Sealing oil pump re-circulating valve wrongly open or is in failure.

Differential pressure regulation valve does not work normally. If it is due to sealing oil strainer block, the strainer should be changed and relevant person should be contacted for treatment. If it is due to sealing oil pump re-circulating valve, the re-circulating valve should be regulated.

If sealing pad leaks oil seriously, it should be reported to the shift manager; if it can not keep running, ask for stopping the unit. If differential pressure regulation valve is in failure, bypass valve can be regulated manually; keep supplying oil to sealing pad and contact with maintenance for treatment.

Closed circulating water system fault Closed cooling water intermits. Closed cooling water head pipe pressure drops or fluctuates. Closed cooling water tank level is low. Closed cooling water pump vibration is high. Closed cooling water pump motor current increases abnormally. Closed cooling water quality gets worse. If closed cooling water head pipe pressure drops, check the working condition of closed water pump: whether closed cooling water tank is too low or not, whether system water discharging valve is strictly closed or not.

If pump output is not sufficient or output pressure is lower than 0. If closed cooling water head pipe pressure fluctuates greatly and motor current fluctuates, it is generally because closed cooling water tank level is low or air enters into pump.

If it is because water tank level low, water should be supplemented to be normal. If it is because pump inlet strainer is blocked with differential pressure 0. If it because air enters into pump, all air discharging valves should be opened to discharge air, standby pump should be immediately transferred for running during gasification. If closed cooling water pump vibrates highly, check whether gasification happens in pump or not, whether there abnormal sounds in pump and pump group bearings or not.

When above abnormities happen, standby pump should be transferred immediately for running. If motor current displays it is increasing, it should be measured.

The reason may be two phases running or bearing damage. Standby pump should be transferred for running. Contact with maintenance for treatment. If closed cooling water quality gets worse, it may due to that supplement water source is polluted.

Water should be changed and contact with chemical for dosing. Auxiliary equipment fault Equipment vibrates heavily and, stator and rotor abrade. Metal friction sound is clear inside equipment. Motor is in smoke or on fire. Bearing is in shortage of oil or in smoke.

Other faults threatening personal and equipment safety happen. Motor current increases abnormally, insulation has burning smell or motor winding temperature exceeds limit. Generator runs with two phases. Gasification occurs in running pump. Bearing temperature exceeds limit.

Air cooling system of big scale air fan is in fault. Gland packing gets hot, smokes or leaks oil or water greatly. Other conditions that threatening auxiliary equipment safety operation happen.

After switch is closed, motor does not run but buzzes. Motor has spark or smoke inside. Motor and its affiliated electric equipments are in smoke and on fire. The mechanical equipment is damaged and can not run. Motor vibrates heavily or impacts inside, stator and rotor abrades. Motor running speed drops acutely, current rises or drops to zero. Motor temperature and bearing temperature rise acutely, which exceed permit values. Flood or fire threatening motor safety occurs.

There is spark or smoke in generator or starting regulation device. Stator current exceeds normal operation value under same load ; Cable down-lead of motor is over heated. Cooling system of large scale motor is in fault.

Motor affiliated machinery is damaged. Motor that tripped due to protector action. Restart it after no problem is confirmed.